.page{
  position: fixed;
  width: 100%;
  height: 100%;
  z-index: 10000;
  top:0;
  left:0;
  background: #f6f6f6;
  transition: .1s;
}
iframe{
  width: 100%;
  height: 100%;
}
#back{
  position: absolute;
  top:70px;
  min-width: 100px;
  height: 30px;
  line-height: 30px;
  background: rgba(0,0,0,0.7);
  color:#fff;
  text-align: center;
  padding:0 15px 0 5px;
  border-radius: 0 15px 15px 0;
}